Supplementary Materials Synthesis of Copper Graphene Materials Functionalized by Amino Acids and Their Catalytic Applications Qiang Huang, Limei Zhou*, Xiaohui Jiang, Yafen Zhou, Hongwei Fan, Wencheng Lang Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong 637002, Sichuan, China. *Author to whom correspondence should be addressed. E-mail: cwnuzhoulimei@163.com.
General Experimental: Graphite powder was purchased from Shanghai Huayi Company (Shanghai, China). CuCl 2 2H 2, KMn 4, NaN 3, H 2 S 4 (98%) and HCl (36%~38%) were obtained from Sinopharm Chemical Reagent Co. Ltd. (Shanghai China). NaBH4, amino acids and imidazole were purchased from Kelong Chemical Reagent Co. Ltd. (Chengdu China). Iodobenzene was obtained from Aladdin Industrial Inc. America. The deionized (DI) water used throughout all experiments was purified to 18.2 MXm with the Millipore system. General Instrumentation: The graphene-copper hybrids were characterized by Scanning Electron Microscopy(SEM, AJEL JSM-6510LV, JAPAN) and X-Ray Diffraction (XRD, D/MAX Ultima IV,JAPAN). X-Ray photoelectron spectroscopy (XPS) was performed using an ESCALAB 250 Xi with a high-performance Al monochromatic source (hυ=1486.6 ev, 150 W). The XPS spectra were taken after all binding energies were referenced to the C1s neutral carbon peak at 284.8 ev, and the elemental compositions were determined from peak area ratios after correction for the sensitivity factor for each element. The powder samples were compressed into a disk. The disk was then attached to a double-sided adhesive tape mounted on a standard sample holder. Acquisition parameters were displayed in Table S1 and S2. Atomic force microscopy (AFM) (Multimode Nanoscope Ⅲa, Veeco Corp, USA) in the tapping mode was used to analyze the thickness and length of the materials. Transmission electron microscopy (TEM) characterization was carried out using a Tecnai G 2 20 field emission electron microscope operated at 200 kv accelerating voltage. Fourier
transform infrared (FT-IR) spectroscopy was performed on a Perkin-Elmar model 2000 FT- IR spectrophotometer using the Spectrum v. 2.00 software package. The amount of copper in catalysts was recorded by inductively coupled plasma atomic emission spectroscopy (ICP- AES WFX-120). Synthesis of graphite oxide: Graphene oxide (G) was synthesized by the oxidation of graphite powder according to the modified Hummer s method. Briefly, 2.0 g graphite powder was mixed to 100 ml concentrated H 2 S 4 in a beaker together with a magnetic stirring rotor, and cooled to around 0 o C. Then 2.0 g NaN 3 and 12.0 g KMn 4 were added stepwise to this solution under continuous stirring and cooling. After 10 min, the brownish suspension was removed from the ice bath and kept the reaction temperature about 38 o C overnight. Next, 120 ml deionized water was slowly added to the paste with vigorous stirring. The temperature rapidly increased to 98 o C and the color of the suspension changed from brown to brightyellow. Then, the reaction mixture was maintained at this temperature for 30 min to increase the oxidation degree of the product, and 25 ml hydrogen peroxide solution (30%, w/w) was added to reduce the excess KMn 4. The prepared graphite oxide could be easily isolated from the solution by vacuum filtration and washed with vast 1.0 mol/l hydrochloric acid. Finally, the crude product was purified by successively washing with deionized water with subsequent centrifugation at 10,000 rpm. Procedure of dispersibility experiment: 5mg A-G-Cu material was added into a screw thread bottle, and 2 ml dimethylsulfoxide (DMS) was injected into the bottle. The mixture was sonicated by ultrasound apparatus for 30min, and then the homogeneous suspension could be obtained. Next, 1mL suspension was fast added into a 1.5 ml centrifugal tube, and taken a picture. After the suspension was aged for 1 h, the dispersion state was recorded by taking a picture again.
Tables: Table S1. Acquisition parameter of XPS analysis for His-G-Cu. Parameter His-G-Cu C1s Cu2p N1s Total acq. time 47.5 secs 6 min 39.9 secs 3 min 0.2 secs No. Scans 5 20 20 Energy Step Size 0.05 ev 0.05 ev 0.05 ev No. of Energy Steps 381 801 361 Source Type Al K Alpha Spot Size 500 µm Lens Mode Standard Analyser Mode CAE : Pass Energy 30.0 ev Table S2. Acquisition parameter of XPS analysis for Lys-G-Cu. Parameter Lys-G-Cu C1s Cu2p N1s Total acq. time 47.5 secs 1 min 40.0 secs 3 min 0.2 secs No. Scans 5 5 20 Energy Step Size 0.05 ev 0.05 ev 0.05 ev No. of Energy Steps 381 801 361 Source Type Al K Alpha Spot Size 500 µm Lens Mode Standard Analyser Mode CAE : Pass Energy 30.0 ev
Table S3. The structure of amino acids. Reagent Name Structure Name Structure L-proline N H L-lysine H 2 N NH L-threonine H L-arginine H 2 N N H Glycine H 2 N L-histidine H N N L-phenylalanine L-glutamic acid H L-tyrosine H L-tryphophan HN Table S4. Abbreviations of the as-prepared catalysts. Amino acids Abbreviation of catalysts Amino acids Abbreviation of catalysts L-proline Pro-G-Cu L-lysine Lys-G-Cu L-threonine Thr-G-Cu L-arginine Arg-G-Cu Glycine Gly-G-Cu L-histidine His-G-Cu L-phenylalanine Phe-G-Cu L-glutamic acid Glu-G-Cu L-tyrosine Tyr-G-Cu L-tryphophan Trp-G-Cu
Table S5. The effect of different reaction parameters on the Tyr-G-Cu (9.7 wt% Cu) composite catalyzed N-arylation reaction of iodobenzene and imidazole. Entry Base Time Temperature ( o C) Yield (%) 1 Li 24 110 87.5 2 Na 24 110 93.2 3 K 24 110 94.4 4 Na 2 C 3 24 110 32.0 5 K 2 C 3 24 110 49.2 6 Cs 2 C 3 24 110 73.3 7 K 3 P 4 24 110 84.3 8 Et 3 N 24 110 5.5 9 Na 24 100 90.9 10 Na 24 90 62.8 Table S6. XRD analysis of the all as-prepared copper graphene hybird materials. Diffraction peak of copper (2θ) Catalysts Amino acids Cu (wt%) Cu Cu 2 Cu Gly-G-Cu Glycine 8.2 - - 43.3 (111) Phe-G-Cu L-phenylalanine 8.3 - - 43.3 (111) 50.5 (200) Thr-G-Cu L-threonine 8.6 - - 43.3 (111) Tyr-G-Cu L-tyrosine 9.7 32.1 (220) 29.4 (110) - Pro-G-Cu L-proline 7.8-36.7 (111) 43.3 (111) Trp-G-Cu L-tryphophan 9.6 - - - Lys-G-Cu L-lysine 9.8-36.7 (111) 42.7 (200) 73.4 (220) Arg-G-Cu L-arginine 10.0 35.5 (002) 39.2 (200) - - His-G-Cu L-histidine 9.7 - - - Glu-G-Cu L-glutamic acid 6.4 - - -
Figures: Figure S1. FT-IR spectra of the as-prepared copper graphene hybird materials. Figure S2. XRD patterns of the as-prepared copper graphene hybird materials (a and b).
Figure S3. TEM images of different copper amino acids grafted graphene hybrid materials.
Figure S4. The dispersion experiment of G and A-G-Cu materials in DMS. (1) Arg-G-Cu, (2) Phe-G-Cu, (3) Glu-G-Cu, (4) Pro-G-Cu, (5) Thr-G-Cu, (6) Tyr-G-Cu, (7) Glu-G-Cu, (8) His-G-Cu, (9) Trp-G-Cu, (10) Lys-G-Cu.